The invention relates both to such inkjet printers in the form of handheld devices, see e.g. PCT Patent Publication No. WO 2013/120702 A1, as well as in the form of stationary devices, see e.g. European Patent No. EP 1 064 153 B1. In handheld devices, the pump may be a compressed-air pump, in stationary devices, generally a liquid pump. Handheld devices are self-sufficient; like cordless screwdrivers, for example, they are equipped with an internal voltage source, in particular with a rechargeable battery. Stationary devices are generally externally supplied with voltage, e.g. via the normal power grid.
At least one storage container for a liquid that is required for the printing process and flows through the filter, such as, for example, ink, pigments or solvents, is generally part of the inkjet printer. The storage container may be disposed in the housing or detachably connected to the housing; in this regard, reference is made to PCT Patent Publication No. WO 2013/120702A1, the content of disclosure of which belongs to the content of disclosure of the present application in its entirety and is therefore incorporated herein. In practical operation, the storage container needs to be replaced relatively frequently because the liquid is constantly used up during printing and the supply is exhausted after a certain number of printing processes.
The filter also needs to be replaced relatively frequently; at least the filter medium of the filter has to be exchanged. In this case, in inkjet printers according to the prior art, the housing has to be opened in each case, and the filter has to be replaced. This procedure requires some effort and is not suitable for a customer, in particular. However, having an authorized specialist carry out the replacement of the filter entails a lot of effort and also cost. Therefore, it would be desirable to make the replacement of the filter easier. In particular, it should be possible to carry it out without any special tool, preferably without any tool whatsoever. Carrying out the replacement is supposed to be possible as cleanly as possible.
In this case, it is to be taken into account that a filter approximately has a capacity of a few hundred liters; then, the filter medium is exhausted. Typically, the capacity is about 200 liters.